Clamshell bucket



Feb. 24, 1931. e. F. THOMPSON CLAM SHELL BUCKET Filed June 26, 1928 N TOR.

' ATTORNEYS.

Patented Feb. 24, 1931 UNETEE STTES PATENT OFFICE GEORGE F. THOMPSON, OF ERIE, PENNSYLVANIA, ASSIGNOR TO G. WILLIAMS COM- IPANY, OF ERIE, PENNSYLVANIA, A CDRIPORATION OF PENNSYLVANIA CLAMSHELL BUCKET Application filed June 25, 1928.

Clam shell buckets of some forms are pro vided with closing arms and the leverage with which these arms operate is dependent upon their length. Such arms ordinarily swing within the bucket walls in the open position and the length of the lever is limited by the position of the bucket walls relatively to the arm. It has been desirable to provide such arms on some types of buckets with guide sheaves from which the closing and lifting cables may operate with the bucket in closed position. Heretofore this guide sheave has been an extension of the lever arm and it has shortened the effective lever power arm to the extent that the guide sheave projects from said arm. The present invention is designed to so mount the guide sheave as to permit of the full length of power arm. Features and details of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawings as follows Fig. 1 shows a side elevation of a clam shell bucket embodying the invention.

Fig. 2 a section on the line 22 in Fig. 1.

Fig. 3 a section on the line 3-3 in Fig. 1.

Fig. 4 a view of the head of the bucket with the parts in closed position.

1 and 2 mark the bucket members. These are provided with the arms 3 and 4 respectively which are pivoted on pins 5. A head 6 is connected by a link 7 with the bucket 2, the connection being accomplished by a pin 8. A link 9 extends from the head to the bucket member 1 being secured to the bucket member by a pin 10 and to the head by a pin 11.

A power arm 12 is pivotally mounted on the pin 8. A catch block 13 is secured on the pin and locked with the arm 4. It has a catch shoulder 14 which is engaged by a latch 15. The latch is pivotally mounted on a pin 16 carried by the arm 12. The rear end of the latch is engaged by a trip lever 17, the trip lever being pivotally mounted on a pin 18.

A trip arm 19 extends from the trip lever 17 and is operated by a trip line 20 extending through a block 21 hung from the head 6. The tripping may be automatically accom Serial No. 288,362.

plished by a-spring 22, if desired. A cable 23 extends around a power arm sheave 24 at 1 second sheave 27 on the )ower arm and is secured at 28 on the block 13. These parts so far as described are of common construction and operate in a well-known manner.

The end of the power arm is provided with forks 29 and a pin 30 extends through these forks forming a journal for the power arm sheaves 24. An extension 31 is pivotally mounted on the pin 30. The pivotal movement of the extension is limited in one direction by a stop 32 which extends from one fork 29 to the other. The extension is provided with an opening 33 through which a pin 34 extends and guide sheaves 35 are j ournaled on the pin 34. Closure plates 36 are mounted on the ends of the pins and these are secured by means of a bolt 37 to an arm 38 extending from the extension 31. The cable 23 operates against the vguide sheaves 35.

In the operation of the device with the bucket open, the power arm is lowered to engage the latch 15. As it is lowered the guide pulleys 35 engage the edge 1a of the bucket 1 and swing clear of this edge. This permits of the power arm being of the maximum length that is practical with the clearance of the edge 1a. When the bucket is closed the extension 31 resting on the stop 32 limits the movement of the extension and so far as the guiding action, therefore, is concerned the extension is to all intents and purposes a rigid extension of the power arm and the extension is drawn tightly against the stop 32 by the force of the cables as clearly shown in Fig. 4. The guide pulley 35 deflects the cable 23 as it leaves the pulley 24 and thus assures the retention of the cable 23 on the sheave 24 with the bucket in closed position, as shown in Fig. 4. The engaging arc of the guide sheave 35 is always in the line between the support of the cable 23 and its point of leaving the sheave 24 so that in all conditions the line is maintained in position on the sheave 24. Heretofore' this guiding has been accomplished as hereinbefore stated by the use of an extension, as 31 rigid with the ower arm. v

hat I claim as new is 1. In a clam shell bucket, the combination of pivotally connected bucket members; a power arm closing said members; a power arm sheave on the power arm; a line operating the power arm; a pivoted extension on the arm; and a guide sheave on the extension engaging and guiding the line to the power arm sheave.

2. In a clam shell bucket, the combination of pivotally connected bucket members; a power arm closing said members; a power arm sheave; a line acting on the power arm sheave operating'the power arm; a pivoted extension on the arm; a'guide sheave on the extension engaging and guiding the line to the power arm sheave; and astop limiting the movemen oi the extension in one direction.

3. In a clam shell bucket, the combination of pivotally connected bucket members; a head; links connecting the head and bucket members; a power arm pivotally connected to one member; a latch connecting the power arm and the bucket members adjacent to their pivoted connection; a line between the head and arm; a pivoted extension onthe arm; and a guide sheave on the arm engaging the line.

4. In a clam shell bucket the combination of pivotally connected bucket members; a head; iinks connecting the head and bucket members; a power arm pivotally connected to one member; a latch connecting the power arm and the bucket members adjacent to their pivoted connection; a line between the head and arm; a pivoted Xtension on the arm; a guide sheave on the arm engaging the line; and a stop limiting the pivotal movement of the extension in one direction.

In testimony whereof I have hereunto set my hand.

GEORGE F. THOMPSON. 

